In Anne Lamott’s Bird By Bird, there is a chapter entitled ‘Shitty First Drafts’. The basic premise is that you give yourself permission to write something messy and then you go clean it up. That first drafts are always rubbish, anyway.
It is a fairly common idea and one that many writers (and writing teachers) recommend, or at least variations of it; it doesn’t work for everyone, though. There are writers who tinker and tweak that first page or first line until it’s just right. (If this is the way you work, it’s not working for you if you don’t actually finish anything, though.)
I think for many writers, though, the first draft is somewhere in between complete trash and all-shined-up perfection – it’s actually a pretty decent draft. And for writers who work like this, maybe the idea of the ‘shitty first draft’ isn’t so useful. It can feel like you’re pretty much there if you’ve got a ‘pretty decent first draft’ instead. When in fact you’re never looking for the ‘pretty decent’, the ‘it’ll do’. You’re looking for the ‘polished as much as I can polish it’. No matter what you start off with.